Check link for scales



R. J. BURKE CHECK LINK FOR SCALES Dec. 18, 1928.

Filed June 8, 1927 2 Sheets-Sheet l Dec. 18, 1928.

R. J. BURKE CHECK LINK FOR SCALES Filed June 8, 1927 2 Sheets-Sheet 2 RMa j m? W M I 50 tion,

Patented Dec. 18, 1928.

warren sures 1,695,316 PATENT orl-ica;

ROBERT J. BURKE, OF PITTSBURGH, PENNSYLVANIA A SSIGNOR T LINCOLN SCALE'CUMGBATION, TII'TGBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

one: LINK non scams.

mama]; fledlnne 5,1927.v Serial No. 197,399.

This invention relates to scales, and particularly to an improvedconstruction in check links therefor.

Levar scales generallylemplaoyn check arm 5 mmmted on thelscalevleveraind carrying the load pan or platform. In order to maintain thepan or platform level at all times and to guide the check'arm,za-chocklink is provided. Thislink mustbe carefully madeand fitted 1 so that itwill not hind and interfene with the eration of the scale. The knifeedges on which the several parts ofthe-scale are pivotetl m u d withstop ,blocks'so as to prevent relative sidewiaeamnvement of the checkarm scale decor and associated parts,

as such sidewisemovenmnt'would, in all probability, cause binding ozfthecheck link.

When a scale is boxed iorshipment, it is desirable to remove the stopblocks .and separate the bearing members from theiruoorrespending knifeedges, i s-otherwise the knife edges would :hedamaged iii-shipment.There is, therefore, considerable danger, when a soale issot up, of thecheck arm hoingcareless- 1y twisted ordisplacodgnfl thus .permmentlydistorting the check link.

1 provides, check link making a universal joint connection with :thacheok arm and the frame. The check link is preferably pivoted so onblocks, one secured to :the frame and one toithe check arm. These blocksare arranged for notation sidewise of the direction of movement of thecheck link. certain cases a connection need be provided at only one endof the check link.

Inthe aooompanyi drawings which illustrate the preferred em odimeut ofmy Invention, and one [modification thereof,

Figure 1 is a side elevation partly broken away, of a spring platformscale of the drum Ffgure 2 is a top plan view of thecheck link with itsconnecting members,

Figure 3 is an end elevation of the structure shown in Figure 2, s a

Figure 4 is a top plan view of one end of the check link,

Figure 5 is a front elevation partly broken away of a fan type scaleembodying the inven- Figure 6 is a horizontal section taken on the lineVIVI of Figure 5,

Figure 7 is a side elevation partly broken away of the apparatus shownin Figure 6, and

Figure 8 is a horizontal section taken on the lineVIII.- VIII of Figure7. I

Figure 1 shows a scale comprising a base 2, and a column 3 carrying thescaleplatform 4, and the weighing mechanism. The plat form 4 is mountedon a check arm 5. The checkarm is carried onknife edges 6 by a mainlever 7. The main lever is pivoted on knife edges at 8 and is supportedat its outer endby a load spring 9. Theweight is indicated by a drum '10operated by a rack and pinion lli'through a rackioar 12; Thecheck arm 5has a portion 5 extending upwardly within the column. It is connectedthrough a check link 13 to the scale framethat is to say, to the column3. I

The check link is provided at each end with knife edge portions 14 and'15 in substantial alignment with one another. The knife edge portions14 are directed outwardly while the knife edge portion 15 carried by anextension .16 of the check link is directed inwardly and facesan'opening 17 formed in the link. The knife edge portion 15 bearsagainst a side face of a block 18. -A plate 19 is secured to this faceby screws 20 and the knifeedge portions 14 bear against theplate. Theblock 18 lies within the opening 17 provided in the check link. Theconstruction at each end of the check link is the same.

' The blocks 18 are mounted on studs 21 and 22. The stud 22 has a collar23 and a downwardly extending threaded portion 24 by provided with asmooth shouldered portion s 27 topped by a nut 28. The blocks 18 arearranged for free rotation on the shouldered portions 27.

There is no danger of the knife edge portions 14 and 15 becoming bent ordistorted in assembling the scale, or in setting it up after shipment.If the check arm 5 is inadvertently displaced sidewise, one or the otherof the knife edge portions 14 and 15 bears against the blocks 18 or theplates 19 and ill causes the blocks 18 to rotate about their supportingstuds. The scale therefore always operates freely and is not likely tolose its accuracy.

It will he noted from Figure 2 that the check link is provided with anopening 29 to acconnnodate the rack bar 12 This opening is madeconsiderably wider than the rack ha r so that the parts will notinterfere at any time.

Figures 5 to 8 inclusive show the invention applied to a fan type scale,such as is used for weighing candy and the like. This scale comprises abase 36 carrying hearings for knife edges ill of a iain lever 3L. Themain lever 32 carries the customary counter weight 33 and link by whichit is connected to a weight indicator 35. The load carrying member a pan36 mounted on a post 37. The post 3? is carried on knife edges 38 on themain lever It is provided with a sidewise exte' cinearm 39 formingthecheck arm of the scale. he check arm has an upwardly extendingportion 0 which at its top is pivotally connected to a ck link ll. Thecheck link ll is forked at each end, as best shown in Figures 6 and is.One of these forked ends makes pivotal connec'ion with the upstandingend 4C0 of the check arm 39. The other forked end embraces a block l2and is pivotzlv connected thereto by a pin l3. The block 9. in turnpivotallv mounted on the cone points of screws ist passing throughspaced arms o on a bracket it The check link is ada d to swing about theblock ii on a horizontal axis, while the block, in turn, is arranged toswine about a vertical axis. This provides a universal connection forone end of the check link.

The bracket 46 is carried by a shouldered bolt siT threaued into theframe F of the scale. Screws l8 and if), one on each side of the screw al, pass through the bracket l6 and engagelugs 50 formed on the frame F.This provides a means for varying the normal angularitw of the checklink ll so as to place it in parallelism with a line passing through theknife edges 31 and 38, as is required for proper scale action. If it isdesired to raise the pivot pin iii, the screw 49 is backed off in itsthreaded opening and the screw 48 is threaded further in. If it isdesired to lower the pivot pin l3, the screws are turned in the reversedirection.

It is found in practice that the above de scribed arrangement permitsuniversal move-- inent of the check link relative to the frame and thecheck arm. In certain types of scales it is desirable to provide auniversal joint at each end of the check l nk as in the embodiment ofFigures 1 to 4.

lVhile I have illustrated and described certain preferred forms of myinvention, it will be understood that it may be otherwise embodiedwithin the scope of the following claims.

I claim z- 1. In a scale, a check arm, a frame, a block pivotallymounted on the frame, and a check link rockable on the block.

In a scale, a check arm, a frame, studs carried by the check arm and theframe, sleeves on the studs, and a check link pivota iv mounted on thesleeves.

3. In a scale, a check arm, a frame, studs carried by the check arm andthe f ame, sleeves on the studs, and a check link pivotally mounted onthe sleeves, one of the studs being; adjustable so as to change thenorinal inclination of the check link.

4. In a scale, a universally movable check link, and a ale member, thecheck link having an ope; thercthroiurh of greater dimensions than thescale member, the scale member passing tl'irougrh the opening.

5. In a scale, a universally movable cheek link, and a rack bar, thecheck link having an opening therethrough of greater dimensions than therack bar, the rack bar extending through said opening.

6. In a scale, a frame, a block, means for adjusting; the position olthe block relative to the frame, and a check link making universalconnection with the frame through the block.

In testimony whereof I have hereunto set my hand.

ROBERT J. BURKE.

